The Cave of the Condom Stalactites

I'm riding somewhere through South-East Asia in a Tuk-Tuk, speeding through the mountains. We go through villages, then speed up again, circling the mountains - there are many tunnels, or caves, rather, with roads built through them. We're getting smaller as we go, our size reducing, but everything else is getting smaller along with us, so it's hard to notice. Passing through a village we enter another cave, speeding up and driving on the left side, on the ceiling of the right side there hang all these condom stalactites, they look to be used, the driver won't stop to let me take a look, they seem large but that's only because we've been shrinking. It's like some sort of sacred alter hewn into the mountain. I think I remember an explanation from National Geographic for this, the condoms collect water.... Leaving the last of the light behind us we're plunged into complete darkness before rounding a corner, the exit is ahead and light streams through it, there's a motorcycle coming straight at us, it loses control and goes off the edge of a precipice. We pull over to look, the bike and driver are lost somewhere far below, the sunlight doesn't reach into the depths of the cave. It's an abyss. We've seen a lot of accidents on this road, he doesn't want to stop and help, there isn't time, we get back in the tuk-tuk and speed off. I don't know where we're going.